﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace test_first
{
    public class calculator
    {
        public double Add(double a,double b)
        {
            return a + b;
        }

        public double Multipy(double a,double b)
        {
            return a * b;
        }

        public double Substract(double a,double b)
        {
            return a - b;
        }
    }
}
